const formatTime = date => {
  const year = date.getFullYear()
  const month = date.getMonth() + 1
  const day = date.getDate()
  const hour = date.getHours()
  const minute = date.getMinutes()
  const second = date.getSeconds()

  return [year, month, day].map(formatNumber).join('/') + ' ' + [hour, minute, second].map(formatNumber).join(':')
}

const formatNumber = n => {
  n = n.toString()
  return n[1] ? n : '0' + n
}

function randomString(min, max = 108, flag = false) {
  var str = "";
  var range = min;
  var arr = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 
            'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 
            'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 
            'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 
            'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 
            'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 
            'Y', 'Z'];
  if (flag) {
      range = Math.round(Math.random() * (max - min)) + min;
  }
  for (var i=0; i<range; i++) {
      var pos = Math.round(Math.random() * (arr.length-1));
      str += arr[pos];
  }
  return str;
}

module.exports = {
  formatTime: formatTime,
  randomString: randomString
}
